In a minimally invasive surgical (MIS) procedure, a small orifice in the body provides access to internal organs. MIS procedures have led to shorter hospitalizations and lower morbidity and mortality. For patients, this translates to less pain and suffering, smaller scars, and quicker return to normal activities.
Minimally invasive surgical (MIS) procedures include laparoscopic surgery and natural orifice translumenal endoscopic surgery, (NOTES). NOTES involves approaching the abdominal cavity (or other body cavities) through natural orifices such as the mouth or vagina, without creating an incision on the abdominal wall. Surgery is performed through this single natural orifice using a flexible endoscope.
Several challenges make MIS procedures particularly difficult. One challenge is the narrow field of view and lack of depth perception with these techniques. During an open procedure, the surgeon can view the surgical field from different angles and perspectives and the haptic feedback provides a mental three-dimensional (3D) image. Laparoscopy, for example, involves inserting a laparoscopic camera through a separate port for accessing the abdominal cavity from various angles of approach to the target area. The exact relative location of the tip of the endoscope relative to nearby anatomic structures must be accurately known in minimally invasive procedures since surgical targets lie in a retrograde position with respect to the single incision made in these procedures. Determining this position is complicated by the flexibility of the tip of the endoscope that makes it difficult to track its distal orientation.
Pre-operative magnetic resonance imaging (MRI) or computed tomography (CT) scans do not solve the restricted visualization problem in MIS surgery. The actual intra-operative scene differs from pre-operative imagery due to several factors, including patient positioning, gas insufflation to create a working space, tool-tissue interaction, and body movements (such as breathing and heart beat).
Current imaging techniques for MIS procedures are either too complex for real time implementation, require information that may not be readily available, or do not provide the resolution and accuracy needed to avoid complications during surgery.